Various techniques for measuring vibrational circular dichroism spectra using optical subtraction Fourier transform infrared techniques are being developed. In one technique, polarized infrared radiation is passed off-axis into a rapid-scanning Michelson interferometer, and opposed Fresnel rhombs placed in each arm of the interferometer induce right and left circular polarization in the beams. The beams cross at the sample focus, and are then refocused onto a high sensitivity mercury cadmium telluride photodetector. In a second design, the interferometer itself is to be used to induce an elliptical polarization in each output beam, obviating the need for the Fresnel rhombs. These spectrometers will be used to study problems of biochemical importance, such as oncogenesis and the mechanism of ion transport through membranes, and in the development of analytical techniques for prostaglandins. A diffuse reflectance infrared Fourier Transform spectrometer has been built, and methods for the rapid automated quantitative analysis of intact pharmaceutical tablets are being developed.